Machine for cutting tubing



Feb. 6, 1951 B. E. FRANK Erm.

HACHINE FOR CUTTING TUBING 6 Sheets-Sheet l Filed Aug. 27, 1949 ...WNIH

Q. IIVVri 1....-:-5

1 .m1 M Vw Q mr m SQ w\ .wm L \.\v 1/ lllllll linm. ||l \l lI/ l IIVHSMIIIII I.. um S u Mnilhlllllll -mnu :wld v LSI-,J QV

MM i B E FRANK El' AL -Am-HNE FOR CUTTING TUBING Feb. 6, 1951 Filed Aug.V2'?, 1949 Feb. 6, 1951 B. E. FRANK ETAL IACHINE FOR CUTTING TUBING 6Sheets-Sheet 5 Filed Apg. 27, 1949 LIvNN mi, QTW MV@ QQ /NvE-/v-rofeeBee/mno tHeM/f( XJH/v WAnfffev-eava ww MW f' .w AT TolNE-Ys Feb. 6, 1951B. E. FRANK ET AL MACHINE FoR CUTTING TUNING 6 Sheets-Sheet 4 Filed Aug.27. 1949 y WMM/A www l ILJ Feb. 6 1951 B. E. FRANK ET Al.

MACHINE FOR CUTTING TUBING 6 Sheets-Sheet 5 Filed Aug. 27 1949 Feb. l6,1951 la. E. FRANK ET AL 2,549,166

MACHINE FOR CUTTING TUBING Filed Aug. 2T, 1949 T 6 sheets-sheet eTTOBA/E-YS Patented Feb. 6, 1951 MACHINE Fon oUr'rmG TUBING Bernard E.Frank and John W. Armstrong, Roch- 4 ester, N. Y., assignors to GeneralMotors Corporation, Detroit, Mich.. a corporation of Dela- Ware pApplication August 27, 1949, Serial No. 112,793

This invention relates to apparatus for cutting tubing into lengths andits object is to provide apparatus for operating upon continuouslymoving tubing for cutting it into uniform lengths without stoppingmovement of the tubing.

In the disclosed embodiment of the invention,

the length of the tubing to be cut from the supply is determined by thedistance between the cutter and an abutment member engaged by the freeend of the tubing. The cutter and member move with the tubing at thesame rate of speed and while so moving the tubing is cut. The abutmentmember has a lost motion connection with the cutter frame. The tubingrst moves the abutment member without moving the cutter; and. duringsaid movement a servo is caused to start motion of the cutter in thedirection of tubing movement. Then the abutment member picks up thecutter, and cutter tubing and abutment member move as a unit; and,during this movement, the cutter is caused to operate. The apparatusprovides for ejection of the cut lengths of tubing and the return of thecutter and abutment member to a starting position.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Fig. 1 isa fragmentary side view of the appav t-doFigi;

Figs. 5 and 6 are fragmentary side views forming continuation to theright of Fig. i;

Figs. 7 and 3 are sectional views taken respectively on lines i-i and 83 of Fig. 5; A

Fig. 9 is a View drawn to a larger scale than Figs. 1. 5 and 6, andshows a fragment'oi a side portion of the apparatus which will belocated to the right of the fragment shown in Fig. 6;

Fig. l is a view in the direction of arrow i0 of Fie. 9;

Figs. 11, l2 and 13 are sectional views taken resmctively on linesil-ii, ii-ii andiB--It of Fig. 9;

Fig. 14 isa side view of the cutter on a larger scale than Fig. 1;

Fig. 15 is a view of the cutter in the direction orarrow i oiFig. 14;

lli

v claims. (ci. 164-48) Fig. 16 is a view in the direction of arrow IB ofFig. 14;

Fis'.v 17 ls a sectional view on line Il--I'I of' Fig.

Fig. 18 is a sectional view on line lli-I8 of Fig. 15;

Fig. 19 is a sectional view on line l9--I9 of '.Fig. 14:

Fig. 20 is an hydraulic and wiring diagram of the apparatus.

Referring to Figs. 1 to 4, a table 2l is supported by a, frameworkcomprising two legs 22 and two legs 23 joined by two each of angles 24,25 and 2t and by shorter angles 28 at the left and 29 at the right inFig. 1.

Referring to Figs. 14 through 19, a cutter assembly comprises sideplates 3i (Fig. 15) attached to a base 32 which is guided forhorizontalmovement by a dovetail bar 33 attached to a 20 plate 34 whichis xed to the table 2| in Fig. 1.

The plates 3i support a cylinder 35 receiving a piston 36 (Fig. 20)connected by rod si which, as shown in Figs. 18 and 19, is attached to ablock 38 which supports bars 39 and are movable between the sides of aframe 4t, the base of which has grooves ti receiving the tongues ft2 ofa block 3 attached to base 32 and providing an aperture M in alignmentwith an aperture 45 in frame 60, a hole 46 in base 32 and an elongatedhole il in plate 3l. The bars 39 are movable also between plates 49attached to frame lili.- Frame t0 guides for horizontal movementtransverse to the direction of movement of the tubing 2, blocks 5t eachprovided with a pair of clamping jaws 5i adapted to engage the tubing.These jaws are urged apart by spring 52 received by sockets 53 in theseblocks (Fig. 18). Downward movement of the piston in cylinder 35 causesthe bars 39 to force the clamping blocks 50 toward each other to gripthe tubing while the tubing is cut by blade 55, movable between the jaws5i, said blade being attached by a pin 5t to a plate 51 which screws 53attach to block 38. The cutter shavings gravitate through holes tt, 45,46 and ti.

Frame 4B is clamped against a lug 5i of plate 43 by a screw 6d threadedthrough a bar tl which screws 62 attach to base 32.

Base 32 has a lost motion connection with a T-bar i0 which extendsnearly the full oi the machine. This lost motion connection is providedby a pin 63 which a set screw it attaches to base 32, said pin beingreceived by a slot t5 in a bar 68, attached to T-bar it. The amount oflost motion can be varied by adjusting the o5 screw 6i threaded throughbar it. The lost 3 motion is taken up in one direction by a spring 88attached to screw 84 and to a clip 88 attached to T-bar 18, said springoperating to urge the T-bar 18 toward the left so that the right endwall of the slot 65 engages the pin 83.

Referring to Fig. 11, T-bar 18 is attached at intervals along its lensthto U-brackets 1| which support rollers 12 received by rails 13 attachedto the bottom ilange of an angle-bar 14 which is supported above theiloor by several posts 18 as shown in Figs. 5 and 6. Y

Referring to Figs. 9 and 10, the T-bar 18 supports a bracket 88supported by the horizontal upper flanges oi the T-bar and securedthereto by clamp plates 8| threadedly engaged by screws 82 passingthrough holes in horizontal side ilanges 83 of bracket 88. Bracket 88provides an oblong hole 84 which receives a lever 85 pivoted on a shaft86 which extends across the hole and which provides the hub 81 o! acurved lever 88. The lever 85 is provided at its lower lett hand comer(Fig. 9) with a notch 89 which receives a corner of an abutment lever 98pivoted on a pin 9| supported by bracket 88. Lever 98 serves as anabutment member engaged by tubing which travels to the right toward theT-bar 18. Normally the lever 98 rests upon the T-bar and is held thereby the lever 85 which is urged clockwise by a spring 92 attached tolever '88 Vand to a pin 93 attached to bracket 88. The free end of thetubing which moves toward the right will engage the lever 98 and causemovement of the T-bar 18 to the right thereby causing the lever 88 tomove into engagement with a rod 98 attached by screwl 96 to a block 91(Fig. 12)V which screws 98 clamp to the vertical flange of angle bar 14.Block 91 is adjustable along the bar 14 so as to locate the rod 95 inthe proper relation 4 18 but is initiated by hydraulic means comprisinga cylinder |38 containing a piston |3| (Fig. 20) and' connected by a rod|32 with a plate 33 having slot |34 which receives a pin |38 urged tothe left end oi the slot by a spring |35a connected with the pin and therod |32. Pini35 is attached to a lever |38 pivoted on a pin |31supported by a bracket |38 attached to a plate |39 supported by thelower angle bar 28. The upper end of the lever |38 carries a pin |48connected by a link |4| with a pin |42 carried by a bracket |43 whichscrews |44 (Fig. 18) atto the lever 88. The right movement of T-bar 18will therefore cause the lever 88 on the lever 85 to be cammedcounterclockwise to freethe lever 98 which by virtue of engagement withthe moving tubing is caused to move counterclockwise to free the tubingwhich can then pass underneath the beveled surface 94 of the lever 98.Bracket 88 has a beveled surface 99 which the tubing may engage at thetime it is being ejected.

The tubing is ejected toward the observer viewing Fig. 9 and to the leftof the T-bar 18 in Fig. 11. Inverted U-shaped members |88 are attachedto levers |8| which, as shown in Fig. 8, are notched to receive a squareshaft |82 and are clamped thereto by screws |83. Shaft |82 hascylindrical portions |84 (Fig. 1l) journaled in bearings provided bybrackets |85 and bearing caps |86 attached by screws |81 to thebrackets, said brackets being attached to the angles 14 by screws |88.

Referring to Figs. 5 and 7, the shaft |82 is received by a notch in alever I8 which is secured to the shaft by a screw Lever ||8 extendsthrough a hole I I2 in a plate I3 which screws ||4 attach to angle 14. Aspring ||5, attached to lever ||8 and to a pin ||6 attached to plate||3, urges lever ||8 clockwise into engagement with the upper surface ofhole ||2 thereby locating the ejecting members |88 in normal position asshown in Figs. "l, 8 and l1. Lever I8 is attached by rod |1 to anamature ||8 of a solenoid |28 having a magnetizable frame ||9 supportedby brackets |2| and |22 provided by a plate ||3.

The engagement of the tibing with the abutment lever 98 (Fig. 9) startsT-bar 18 moving right in Fig. l. However, motion of the cutter to theright is not initiated by movement of T-bar tach to the base or carriage32 which supports the cutter 38.

The cutter 38 is started moving right by virtue of right movement oiplate |33 connected with rod |32, connected with the piston |3| incylinder |38. Admission of pressure fluid at the left end of cylinder.|38 is controlled by a servo valve |58 (Fig. 20) having an inlet ductI5| connected with a source of pressure fluid to be described and havingdistributing ducts |52 and |53 connected' respectively with pipes |54and |55. Pipe |54v is connected with the left end of cylinder |38, in amanner to be described. Pipe |55 is connected by a valve |98 and a pipeI9I with the right end of the cylinder |38. The valve |88 includes aspooivalve |56 having landsl51 and |58 and'slidable within a i'ollow upsleeve valve |59 connected by rod |59a, pin |68, link |8| and pins |62with a block |83 vwhich can be adjusted along the lever |38 and securedby screws |84. The sleeve valve |59 has a pressure fluid inlet port |65.outlet ports |66 and |61, and a drain port |68. When the valve members|58 and |59 are in equilibrium position as shown in Fig.'20. there willbe some leakage of pressure` fluid, as indicated by the arrows |69, intoa duct |18- which is connected with a drain pipe |1|. A spring |12located between rod |59a and spool valve |56 urges the spool valve rightso that'a cam'follower |13 (Fig. 1) on the right end of spool valve |56will engage a cam |14 integral with a lever |15 pivoted on a rod |16supported by a bracket |11 which is provided by one of the cover members|1-8 oi the valve |58. As shown in Fig. 1, valve |58 is secured byscrews |19 to the plate |39. Lever |15 is attached by screw |88 andnutsf|8| (Fig. 3) to an extension |82 carrying a pin |83 received by asl.ot |84 in a bracket |85 attached to the T-bar 1 Valve |98 (Fig. 20)includes a movable spool valve- |92 having lands |93 and |94 normallypositioned, as shown by a spring |95, located between the valve body anda washer |96 attached to the stem of valve |92.'` Valve |98 thereforenormally connects pipe |9| with pipe |1| and blocks connection betweenpipe |55 and pipe |9|. Hydraulic -uid leaking to the left past the land|93 can escape to pipe I1I. Spool valve |92 is connected with thesolenoid armature |91 which is moved to the right against the action oflspring |88 when a solenoid coil |98 is energized.

The admission of pressure uid to the ends I of cylinder is under controlby valve 288 having a movable spool valve 28| connected with solenoidarmatures 282 and 283 under control by solenoid coils 284 and 285respectively. When spool valve 28| is in the position shown, a pipe 286connected with a source of pressure iluid is connected with the lowerend of cylinder 35 through pipe 281 While the upper end of the cylinderis connected by a pipe 288 with drain pipe 289. When coil 285 isdeenergized and coil |56 toward the l 204 is energized, spool the piston36 moves down to effect the clamping of the tubing and the cuttingthereof; andfvic'e versa, when the coil 204 fs deenergized and coil 203is energized, the piston 36 moves-up toretract the shcar blade and tounclamptheftubing.

in Figs. 14 and 15, to plates 3 4 'and a switch SW3 attached to a plate3| of cutter 30. These switches have actuators 22|,.222, 223 and 224respectively. One plate 3| of the cutter carries pins 225 and225pivotall supporting cams 221 and 228 connected by a spring 229 whichurges cloc wise agai11st-s`ttrp`.pix1 s 230 and 23| respectively. SwitchSWI has a movable contact IC which is held down against the action of aspring Is to connect wires 2x and 2m (Fig. 20) when the cutter 30 is inthe position shown. As the cutter moves right it retracts cam 221 fromactuator 22|. Spring Is moves contact lc up to break connections betweenwires 2r and 2m and to make the connection between 2m and 2y.

Switch SW2 is a` normally closed switch connecting wires 2` and 2.1:.When opened by engagement of cam 228 with actuator 222 for a periodduring right movement of cutter 30, wires 2 and 2n: are disconnected.Switch SW4 is a normally open switch which is caused to be moved down byengagement of cam 228 with actuator 223 to connect wires 1 and 8.

Switch SW3 has a contact 3c which is held up against the action ofspring 3s to connect Wires 3 and 1 due to the engagement of its actuator224 with a bar 224D which, as shown in Figs. 14, and 17, is attached tothe block 38. Therefore, while piston 36 is uppermost, wire 3 isconnected with wire 1 but disconnected from wire 6. Downward movement ofpiston 36 permits spring' 3s to move contact 3c downward to disconnectwires 3 and 1, and to connect wires 3 and 6.

Switches SWI, SW2, SW3 and SW4 control the circuits of coils 23|, 232,233 and 234 of relays REI, RE2, RE3 and RE4.

While coil 23| of relay REI is not energized no connections are made bythis relay but when coil 23| is energized wires 2y and 2m are connectedwith wire 2z.

When coil 232 is not energized relay RE2 connects wires 2 and 3 and whencoil 232 is energized wire 2 is disconnected from wire 3 and isconnected with wire 4.

When coil 233 of the relay RE3 is not energized wires 2 and 2z areconnected and when coil 233 is energized wire 2 is disconnected fromwire 2z and eject solenoid coil |20 is connected with wires IIa and |2a.

When fluid pressure exceeds valve moves to the i left to connect pipe206 with pipe 208 connectedv with the upper end of cylinder 35, whilethe .i

When coil 234 of relay R134 is energized cui rent source wires il and I2are connected with fwircs IIa and |2a, respectively with which coil |98is connected.

-coil 204 is energized and coil 205 is dcenerg'ized".

Wires and 2 and wires II and I2 are con- Vnected'with suitable currentsource.

` lows: When the cutter is in the left or normal position shown in Fig.14, switch SWI connects wires 2m and 2.1:. Therefore. coil 23| of relayREI is energized through the following circuit: wire I, coil 23|, wire2m, switch SWI, wire 23:, switch SW2, wire 2.. Relay REI then connectswire 2z with the wires 2y and 2m. Coil 23| of relay REI is thenconnected with wires I and 2 through a circuit independent of switchesSWI andtSWZ, namely, wire I, coil 23|, wire 2m, wire 2z, upper contactsof relay RE3, wire 2. Therefore, the circuit of coil 23| is maintainedindependently of switches SWI and SW2 until coil 233 of relay RE3 isenergized to disconnect wires 2 and 2e.

When the tubing which moves right engages the stop lever 90 (Fig. 9) andcauses the T-bar 10 to move right, before lost motion is taken upbetween screw 61 and pin'63 (Fig. 18), lever |15 (Fig. 1) has been movedby the T-bar clockwise suiiiciently to cause movement of spool valve |56(Fig. 20) to the right relative to the sleeve |59 thereby causingadmission of pressure uid to the left end of the cylinder |30 to causeright movement of piston |3| and bar |33 and thereby starting the rightmovement of the cutter 30 in advance of movement of the cutter by theT-bar 10 which is moved by the tubing. This feature is important onaccount of the inertia of the cutter. The tubing would buckle if it hadthe duty of initiating cutter movement. The T-bar 10, which is travelingat the rate of speed of the tubing, actually moves at a rate faster thanthe rate of the right movement of the cutter when moved by the piston|3| so that the cutter 30 does not push the T-bar but is pulled therebyby virtue of engagement of screw 6'! (Fig. 18) with pin 63. The tubingcan perform, without buckling, the function of accelerating the movementof the cutter. Therefor,l the cutter, tuby ing and abutment member 90an'l T-bar 10 move as a unit for a time during which the tubing isclamped and cut. The clamping and cutting operations takev placeimmediately after the cutter 30 has been moved by the moving tubing tothe right (Fig. 14) sufliciently to allow switch contact I c to breakconnection between wire 2m and 2m and to make connection between wire 2zand wire 2y. When this occurs coil 232 of relay RE2 is energized throughthe following circuit: wire I, coil 232, wire 2z, closed contacts ofrelay REI, wire 2y, switch SWI, Wire 2x, switch SW2 (still closed) andwire 2. When coil 232 is energized wire 2 is disconnected from wire 3and is connected with wire 4 thereby causing energization of coil 204while coil 205 is not energized. Therefore, the spool valve 20| movesleft to connect pipe 206 with pipe 208 so that uid pressure is appliedto the top of `piston 36 and it moves down to effect the clamping c-fthe tubing and the cutting thereof before the cutter 30 has moved to theright sufficiently to onen switch SW2. When SW2 is opened, coil 232 ofrelay RE2 is deenergized and coil 204 is open circuited and wire 2 isconnected with wire 3. Therefore. by the time the cutter blade has moveddown sulciently to cut the tubing, contact 3c of switch SW3 hasconnected wires 3 and 6 and coil 205 is energized through the followingcircuit: wire l, coil 205, wire 6, switch SW3, wire 3, upper contact ofrelay RE2, wire 2. Therefore, the cutter blade movesv up and switch SW3is caused to disconnect wire 3 from wire 6 whereupon coil 205 isdeenergized and wire 3 is connected with wire 'I. When this occurs coil230 of relay REQ is energized through the following circuit: wire I,coil 234, wire l, switch SW3, wire 3, relay REZ, wire 2. Relay REll thenconnects current source wires |'I and I2 with coil |98 so that valve |90is conditioned to cause pressure fluid to flow from pipe |55 to pipe I9|to the right end of the cylinder |30. Coincidentally, when the tubinghas been severed, eject solenoid |20 becomes energized throughconnections with wires |Ia and |2a effected by virtue of energization ofcoil 233 of relay RE3 which takes place by the closing of switch SW atthe end of the right movement of cutter 30. Coil 233 is then energizedthrough the following circuit: wire I, coil 233, switch SWG, wire "I,switch SW3, wire 3, relay REZ, wire 2. The free length of tubing istherefore. ejected. Just prior to ejection and coincidentally with theclosing of the switch SWI, the lever 88 has been cammed by engagementwith rod 95 (Figs. 9 and 12) into position for releasing the stop lever90. Therefore right movement of T-bar I ceases and left movement beginsby virtue of the action of spring |35a (Fig. 1) which can pull the pin|35 to the left and lever |36 counterclockwise thereby causing leftmovement of the T-bar 'I0 by engagement of pin 63 (Fig. 18) with screw67. Therefore the cutter and the T-bar start moving left as a unit..However, due to the action of cam |14 upon follower |13, spool valve |56(Fig. 20) will move faster toward the left than sleeve valve |59.Therefore, there will be relative displacement of valve |56 to the leftof valve |59. Therefore, at the time coil |98 of valve |90 is energizedso as to connect pipes |55 and |9, valve |50 will be conditioned forconnecting pipes 2M and |55. Therefore, the piston |3| will move to theleft and cause the spring I 35a to be stretched and thereby to pull thelever |36 counterclockwise and the cutter 30 to the left, therebycarrying the cutter and the T-bar back to the normal or startingposition corresponding to which the valve |50 is in equilibrium status.As soon as the cutter starts moving left switch SW4 opens and coil 233of relay RES is deenergized and the eject solenoid |20 is deenergized sothat the ejector members |00 (Fig. 8) return to normal position toreceive the uncut tubing as it moves along the T-bar 10. However, coil234 of relay RE remains energized and coil |98 remains energized so thatvalve |90 will remain in condition to maintain connection of pipes |55and I9I so that the cutter 30 will be moved back to starting position.Return of spool valve member |92 of valve |90 is caused by spring |95when coil |98 is deenergized. Decnergization of coil |98 is caused earlyin the next cycle when coil 234 of relay RE4 becomes deenergized due tooperation of relay RE2 to break connection b-t\veen wires 2 and 3.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. Apparatus for cutting tubing into lengths comprising a cutter unitmounted for movement with the tubing and through which the tubing meanslongitudinally and having a blade movable transversely of the tubing andhaving means for moving the blade, a tubing support which receives thetubing as it passes from the cutter unit and which is movable with thetubing, an abutment carried by the tubing support and engagable by thetubing whereby the support moves with the tubing, a connection betweenthe support and cutter unit providing lost motion, a spring connecting,the support and cutter unit for taking up the lost motion in onedlrecion so that the support can move a short distance before the cutterunit moves with the support, means rendered effective by initialmovement of the support to start movement of the cutter unit at a rateslower than tubing movement and rendered effective by the initial returnmovement of the support after release of the abutment from engagement bythe tubing to return the cutter unit and support to starting position,means for effecting initial return movement of the support after theabutment member has released the tubing, means for causing operation ofthe blade moving means to cut the tubing and then to retract the bladeduring movement of the cutter unit with the tubing, a latch carried bythe support for retaining the abutment in functioning position, meansfor causing retraction of the latch in response to further movement ofthe support whereby the tubing actuates the abutment intonon-functioning position and means for causing ejection of the cuttubing.

2. Apparatus for cutting tubing into lengths comprising a cutter unitmounted for movement with the tubing and through which the tubing moveslongitudinally, and having a blade movable transversely of the tubingand having means for moving the blade, a tubing support which receivesthe tubing as it passes from the cutter unit and which is movable withthe tubing, an abutment carried by the tubing support and engageable bythe tubing whereby the support moves with the tubing, a connectionbetween the support and cutter unit providing lost motion, a springconnecting the support and cutter unit for taking up the lost motion inone direction so that the support can move a short distance before thecutter unit moves with the support, a servo for moving the cutter unit,a servo controller, a mechanism for operating the controller by initialmovement of the support by the tubing to cause the servo to move thecutter unit in the direction of tubing movement at a rate less than therate of tubing movement and for operating the controller, during thefirst part of return movement of the support, to cause the cutter unitand support to return to starting position, a connection between theservo and cutter unit providing lost motion whereby the cutter unit canmove with the tubing independently of the servo and the cutter unit andsupport can move a distance toward starting position after the supportis released from connection with the tubing, means for causing the firstpart of return movement of the support whereby the servo controller isconditioned for return of the cutter unit and support, means for causingoperation of the blade moving means to advance the blade to cut thetubing and to retract the blade while the cutter unit moves with thesupport, a latch carried by the support for retaining the abutment infunctioning position, means for causing retraction of the latch inresponse to further movement of the support whereby the tubing actuatesvthe abutment into non-functioning position and means for causingejection of the out tubing.

3. Apparatus for cutting tubinginto lengths comprising a cutter unitmounted for movement with the tubing and through which the tubing moveslongitudinally and having a blade movable transverselyY of the tubingand having means for moving the blade, a tubing support which receivesthe tubing as it passes from the cutter unit and which is movable withthe tubing, an abutment carried by the tubing lsupport and engageable bythe tubing whereby the support moves with the tubing, a connectionbetween the support and cutter unit providing lost motion, a springconnecting the support and cutter unit for taking up the lost motion inone direction so that the support can move a short distance before thecutter unit moves with the support, a servo for moving the cutter unit,a controller for the servo causing it to move the cutter unit at a rateslower than the rate of tubing movement, means connected with thesupport and operating during the initial movement of the support by thetubing to condition the controller for operation of the servo to movethe cutter unit in the ldirection of tubing movement before the lostmotion connection is taken up in the direction opposite to that iirstmentioned whereby the cutter unit is in motion before the support beginsmoving it, a connection between the servo and the cutter unit providinga second lost motion connection so that the cutter is moved by thesupport independently of operation of the servo, a second spring whichtakes up in one direction the lost motion of the second mentionedconnection and which yieldingly resists movement of the cutter unit bythe tubing, means operating in response to movement of the cutter unitwith the support forv causing the blade moving means to cause the bladeto advance to cut the ltubing and then to retract, means normallyretaining the abutment in functioning position and rendered ineffectivein response to movement of the support following blade return wherebythe abutment is moved by the tubing to non-functioning position, atubing ejector, means for causing operation of the ejector in responseto a movement of the cutter unit with the tubing coincidently withretraction of the abutment member, said second mentioned spring becomingeiective upon retraction of the abutment member to initiate return ofthe tubing support toward starting position, said servo controller beingconditioned by said initial return movement for causing the servo toreturn the cutter unit to starting position whereby the return of thesupport to starting position is eifected by the return movement of thecutter unit in conjunction with the iirst mentioned spring whichrestores the intial status of the first men tioned lost motionconnection.

4. Apparatus according to claim 1 in which the means rendered eiectiveby initial movement of the support to start movement of the cutter unitat a rate slower than tubing movement and rendered effective by theinitial return movement of the support after release of the abutmentfrom engagement by the tubing to return the cutter unit and support tostarting position, comprises an hydraulic servo cylinder and pistonhaving a lost motion connection with cutter unit, a servo control valvehaving a spool valve providing spaced lands, having a sleeve valveproviding ports normally closed by the lands and an intermediate portand a body providing a fiuid pressure inlet duct connected with theintermediate port and distribution ducts connected respectively with theother ports of the sleeve valve and revthe position of the spool valveto cause, in response to initial movement of the support with the tubingflow of pressure fluid from the intermediate port of the sleeve valve tothat port which is connected with that end of the cylinder required foreffecting movement of the cutter unit in the direction of movement ofthe tubing, said ports being of such small size that the servo moves thecutter unit at a rate less than the rate of tubing movement, amechanical connection between the servo piston and the sleeve valve toprovide for the movement of the sleeve valve to distribution portvclosing position at the end of piston travel, said spool valvepositioning means operating during the initial return movement of thesupport, to effect displacement of the spool valve relative to thesleeve valve for the purpose of connecting the iiuid pressure inlet ductwith the other end of the servo cylinder whereby the cutter unit andsupport are returned to starting position.

5. Apparatus according to claim l in which blade moving means comprisesan hydraulic servo cylinder and piston, in which the means for causingoperation of the blade moving means comprises a valve for selectivelyconnecting a fluid pressure source with the ends of the cylinder, afirst solenoid for conditioning the valve for effecting advancement ofthe blade to the tubing, a second solenoid for conditioning the valvefor effecting retraction of the blade, in which the means for causingejection of the tubing includes a third solenoid, and in which thecontrol of said solenoids is effected by an electrical system includingfirst, second, third and fourth switches, the first, second and fourthswitches being controlled by position of the cutter unit, the thirdswitch being controlled by position of the servo piston, the firstswitch making a rst circuit connection when the cutter unit is atstarting position and a second circuit connection when the cutter unitmoves from starting position, the second switch being normally closedand opening by movement of the cutter unit when travelling with thetubing, the fourth switch being normally open and closed by movement ofthe cutter unit with the tubing after the opening of the second switch,the third switch having a first circuit making position when the bladeis retracted and a second circuit making position when the blade isadvanced to cut the tubing, rst, second and third relays having magnetcoils current source terminals, a circuit connecting the rst relay coilwith the terminals and comprising the first switch in first position andthe second switch in normal position, a circuit connecting the firstrelay coil with the terminals after energization of the rst relay coiland comprising contacts of the first relay and normally closed contactsof the third relay, a circuit connecting the second relay coil `with theterminals and comprising contacts of the first relay, the rst switch insecond position and the normally closed contacts of the second switch, acircuit connecting the first solenoid with the terminals and includingcontacts of the second relay when energized, said first solenoid beingdeenergized when the second switch opens to efi'ect open-circuiting thesecond relay coil, a circuit for connecting the second solenoid with theterminals and comprising the third switch in second position andcontacts of the second relay when deenergized, the second solenoid beingdeenergized when the third switch returns to first position, a circuitfor connecting the third relay coil with the terminals and including thefourth switch when closed, the third switch in rst position and contactsof the second relay when deenergized, means for connecting the thirdsolenoid with a current source including contacts of the third relaywhen energized, energization of the third relay causing its normallyclosed contacts to open whereby the rst relay coil is deenergized, thethird relay coil being deenergized when the fourth switch opens inresponse to the first part of return movement of the cutter unit, thethird solenoid being deenergized in response to deenergization of thethird relay, and the first relay coil being reenergized when the cutterunit returns to starting position whereby the cycle is repeated when thecutter unit moves in the direction of tubing movement.

6. Apparatus according to claim 1 in which blade moving means comprisesan hydraulic servo cylinder and piston, in which the means for causingoperation of the blade moving means comprises a valve for selectivelyconnecting a fluid pressure source with the ends of the cylinder, afirst solenoid for conditioning the valve for effecting advancement ofthe blade to the tubing, a second solenoid for conditioning the valvefor effecting retraction of the blade, in which the means for vcausingejection of the tubing includes a third solenoid, means for preventingoperation of the means which returns the cutter unit and support, afourth solenoid for disabling the preventing means when energized, andin which the control of said solenoids is effected by an electricalsystem including rst, second, third and fourth switches, the first,second and fourth switches being controlled byposition of the cutterunit, the third switch being controlled by position of the servo piston,the first switch making a rst circuit connection when the cutter unit isat starting position and a second circuit connection when the cutterunit moves from starting position, the second switch being normallyclosed and opening by movement of the cutter unit when travelling withthe tubing, the fourth switch being normally open and closed by movementof the cutter unit with the tubing after the opening of the secondswitch, the third switch having a first circuit making position when theblade is retracted and a second circuit making position when the bladeis advanced to cut the tubing, first, second, third and fourth relays,having magnet coils current source terminals, a circuit connecting thelrst relay coil with the terminals and comprising the first switch inrst position and the second switch in normal position, a circuitconnecting the rst relay coil with the terminals after energization ofthe first relay coil and comprising contacts of the first relay andnormally closed contacts of the third relay, a circuit connecting thesecond relay coil with the terminals and comprising contacts of the rstrelay, the

first switch in second position and the normally closed contacts of thesecond switch, a circuit 12 connecting the first solenoid with theterminals and including contacts of the second relay when energized,said rst solenoid being deenergized when the second switch opens toeffect opencircuiting the second relay coil, a circuit for connectingthe second solenoid with the terminals and comprising the third switchin second position and contacts of the second relay when deenergized,they second solenoid being deenergized, when the third switch returns torst position, a circuit for connecting the fourth relay coil with theterminals and including the third switch when in first position andcontacts of the second relay when deenergized, means for connecting thefourth'solenoid with a circuit source and including contacts of thefourth relay when energized, a circuit for connecting the third relaycoil with the terminals and including the fourth switch when closed, thethird switch in rst position and contacts of the second relay whendeenergized, and a circuit for connecting the third solenoid with acurrent source including contacts of thel fourth and third relays whenenergizedenergiza tion of the third relay causing its normally closedcontacts to open whereby the rst relay coil is deenergized, the thirdrelay coil being deenergized when the fourth switch opens in response tothe rst part of return movement of the cutter unit, the third solenoidbeing deenergized in response to deenergization of the third relay, thefourth relay coil being deenergized when the second relay coil isenergized and the rst relay coil being reenergized when the cutter-unitreturns to starting position whereby the cycle is repeated when thecutter unit moves in the direction of tubing movement.

7. Apparatus according to claim 1 in which blade moving means comprisesan hydraulic servo cylinder and piston, in which the means for causingoperation of the blade moving means comprises a valve for selectivelyconnecting a fluid pressure source with the ends of the cylinder, a rstsolenoid for conditioning the valve for effecting advancement of theblade to the tubing, a second solenoid for conditioning the valve foreffecting retraction of the blade, in which the means for causingejection of the tubing includes a third solenoid and in which the rstsolenoid is energized in response to first part of movement of thecutter unit with the tubing and the third solenoid in response to latterpart of movement of the cutter with the tubing and in which the secondsolenoid is energized in response to advancement of the blade to cut thetubing.

BERNARD E. FRANK. JOHN W. ARMSTRONG.

REFERENCES CITED UNITED STATES PATENTS Name Date Borzym June 25, 1940Number

